pollution vs befoulment

pollution and befoulment both are nouns.

Word	Noun	Adjective	Verb	Adverb
pollution	Yes	No	No	No
befoulment	Yes	No	No	No

As nouns, pollution and befoulment are synonyms defined as:

Other synonyms of pollution include defilement.

pollution (noun)	befoulment (noun)
the act of contaminating or polluting; including (either intentionally or accidentally) unwanted substances or factors	the state of being polluted
undesirable state of the natural environment being contaminated with harmful substances as a consequence of human activities
the state of being polluted